Help & FAQ
How to use the Unit Converter
How to use the unit converter
- Pick a category such as Length or Temperature.
- Type a value and choose the units to convert from and to. Use the swap button to reverse the direction.
- The result updates instantly, with the one-unit conversion factor shown underneath.
How conversions are calculated
Every unit in a category is defined by how many base units it contains — for length the base is the metre, for mass the kilogram. A value is multiplied into the base unit and then divided by the target unit's factor. Temperature is the exception because its scales don't start at the same zero, so it uses formulas:
- °F = °C × 9 ÷ 5 + 32
- °C = (°F − 32) × 5 ÷ 9
- K = °C + 273.15
Conversion factors
Length (base unit: metre)
| Unit | Equals in metres |
|---|---|
| Millimetre (mm) | 0.001 |
| Centimetre (cm) | 0.01 |
| Metre (m) | 1 |
| Kilometre (km) | 1000 |
| Inch (in) | 0.0254 |
| Foot (ft) | 0.3048 |
| Yard (yd) | 0.9144 |
| Mile (mi) | 1609.344 |
| Nautical mile (nmi) | 1852 |
Weight / mass (base unit: kilogram)
| Unit | Equals in kilograms |
|---|---|
| Milligram (mg) | 0.000001 |
| Gram (g) | 0.001 |
| Kilogram (kg) | 1 |
| Tonne (t) | 1000 |
| Ounce (oz) | 0.028349523125 |
| Pound (lb) | 0.45359237 |
| Stone (st) | 6.35029318 |
Area (base unit: square metre)
| Unit | Equals in square metres |
|---|---|
| Square centimetre (cm²) | 0.0001 |
| Square metre (m²) | 1 |
| Hectare (ha) | 10000 |
| Square kilometre (km²) | 1000000 |
| Square inch (in²) | 0.00064516 |
| Square foot (ft²) | 0.09290304 |
| Square yard (yd²) | 0.83612736 |
| Acre (ac) | 4046.8564224 |
| Square mile (mi²) | 2589988.11034 |
Volume (base unit: litre)
| Unit | Equals in litres |
|---|---|
| Millilitre (mL) | 0.001 |
| Litre (L) | 1 |
| Cubic metre (m³) | 1000 |
| Teaspoon (US) (tsp) | 0.00492892159375 |
| Tablespoon (US) (tbsp) | 0.0147867647812 |
| Fluid ounce (US) (fl oz) | 0.0295735295625 |
| Cup (US) (cup) | 0.2365882365 |
| Pint (US) (pt) | 0.473176473 |
| Gallon (US) (gal) | 3.785411784 |
| Gallon (UK) (gal (UK)) | 4.54609 |
Speed (base unit: metre per second)
| Unit | Equals in metre per seconds |
|---|---|
| Metres per second (m/s) | 1 |
| Kilometres per hour (km/h) | 0.277777777778 |
| Miles per hour (mph) | 0.44704 |
| Knot (kn) | 0.514444444444 |
| Feet per second (ft/s) | 0.3048 |
Time (base unit: second)
| Unit | Equals in seconds |
|---|---|
| Millisecond (ms) | 0.001 |
| Second (s) | 1 |
| Minute (min) | 60 |
| Hour (h) | 3600 |
| Day (d) | 86400 |
| Week (wk) | 604800 |
| Year (365 days) (yr) | 31536000 |
Data size (base unit: byte)
| Unit | Equals in bytes |
|---|---|
| Bit (bit) | 0.125 |
| Byte (B) | 1 |
| Kilobyte (1000 B) (kB) | 1000 |
| Megabyte (1000² B) (MB) | 1000000 |
| Gigabyte (1000³ B) (GB) | 1000000000 |
| Terabyte (1000⁴ B) (TB) | 1000000000000 |
| Kibibyte (1024 B) (KiB) | 1024 |
| Mebibyte (1024² B) (MiB) | 1048576 |
| Gibibyte (1024³ B) (GiB) | 1073741824 |
| Tebibyte (1024⁴ B) (TiB) | 1099511627780 |
Why does 1 GB show as 1000 MB and not 1024?
Storage makers and most operating systems on phones use decimal units (1 GB = 1000 MB). Windows and many technical tools use binary units, properly called GiB and MiB (1 GiB = 1024 MiB). Both are listed so you can pick the right one.
Are the US and UK gallon the same?
No. A US gallon is 3.785 litres and an imperial (UK) gallon is 4.546 litres. Cups, pints and fluid ounces here are US measures.
How accurate are the conversions?
Factors use exact international definitions where they exist (for example 1 inch = 2.54 cm exactly, 1 pound = 0.45359237 kg). Results are shown to up to eight decimal places.